ML19316B131
| ML19316B131 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 06/05/1980 |
| From: | Parker W DUKE POWER CO. |
| To: | Harold Denton, Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8006110354 | |
| Download: ML19316B131 (2) | |
Text
. __
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June 5, 1980 VsCE Pettiotee?
TELgPmQlet: ASEE 7Q4 Seta= paoovet,o 37 3-4c e s Mr. H. R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Mr. B. J. Youngblood, Chief Licensing Branch No. 1
Subject:
McGuire Nuclear Station Docket Nos. 50-369, 50-370
Dear Mr. Denton:
We have reviewed Mr. Robert L. Baer's letter of April 9, 1980 requesting an independent plant wide audit of the installation of safety-related equipment and cables at McGuire. As indicated in your April 9, 1980 letter and in your November 30, 1979 letter on this matter, the purpose of this audit would be to verify the field implementation of the McGuire separation criteria. As a result of both letters referenced above we have reviewed the procedures and mechanisms for locating and installing safety related electrical equipment and cabling. We continue to believe that the many levels of checks and reviews of our nuclear safety-related work by Design, Construction, Quality Control,and Quality Assurance personnel provide adequate assurance that the McGuire separa-tion criteria is properly implemented.
In addition to the many levels of checks and reviews of nuclear safety-related work, it is important to reiterate the fact that cables at McGuire are routed by computer. Our computer routing program was developed in 1969 and used in the design and construction of Oconee Unit 3, therefore, we do have several years of experience and confidence with routing cables by computer. Once the cables are routed, they are then installed in the plant by the Construction Department in accordance with the computer routing cards. To aid in the instal-lation of cables not only are the safety-related cables themselves identified by a color code system but also the cable tray system is clearly identified by the color code.
Another factor which should be considered is the exclusive use of armored cable throughout the station. This design has been tested extensively and shown to be effective for electrical, electromagnetic, electrostatic and mechanical isolation. The use of armored cable assures that internal cable faults within a given cable will not damage adjacent cables or cause fires in any cable system.
Jool s
3006110354
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'Mr. H. R. Denton, Director June 5, 1980 Page Two In our letter of December 26, 1979 we stated that our review of the mechanisms and procedures used to route cables did reveal one area of design where addi-tional attention was warranted. The area identified involved routing and separa-tion situations for non-safety-related cables routed with safety-related cables.
In accordance with our commitment to review this matter, we have performed a design review of these Unit 1 cables. A total of 13,987 non-safety-related cables were checked for proper separation. Of these 13,987 cables, only 14 cables (0.10%) were determined to have been assigned incorrect routing restric-tiors;t.
It is important to note that although the assignment of the wrong restric-tion code to these 14 cables resulted in inappropriately applied separation criteria, the cables were installed in accordance with the computer routing cards (i.e. there were no installation errors).
Based on the extremely small number of discrepancies discovered during our design review of the non-safety cables and the fact that the safety cables and trays _are color coded, we do not feel an additional audit audit is warranted.
Additionally, the magnitude of the effort which would be required to perform
- he requested audit would not, in our judgment, be justified. If you feel that additional discussions are necessary, please feel free to contact us as we are anxious to resolve this matter.
4 Ve truly yours i h.
William O. Parker, J.
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